Tumor markers, measured in peripheral blood, could assist in diagnosis and management of non-small cell lung cancer (NSCLC) and potentially improve historically dismal outcomes. Circulating antibodies, generated to a wide range of tumor-associated proteins, can be translated into a valuable blood test for lung cancer. Preliminary data supports this hypothesis. We have successfully used phage-display, biopan enrichment techniques and high throughput fluorescent array screening to identify multiple known and unknown tumor-associated proteins specifically recognized by circulating tumor-associated antibodies NSCLC patients but not in normals. A panel of phage-expressed proteins arrayed on a glass slide microarray used to measure tumor-associated antibodies in serum from a cohort of cancer patients and risk-matched controls affords predictive accuracy that exceeds that of currently available circulating NSCLC-associated protein markers. Although fluorescent microarray system is an ideal tool for identifying proteins recognized by tumor-associated antibodies, it is not a commercial-ready platform. The intent of this proposal is to incorporate these markers into a layered protein array (LPA), a 96-well ELISA type platform that has been developed for clinical diagnostics. The high-throughput format of the LPA allows measurement of multiple antibody markers simultaneously will be central to the application is a perfect complement to biomarker identification. The LPA will be initially constructed and tested using a panel of proteins that have already been identified. Our initial application will be early detection of lung cancer, although multiple applications in lung cancer management are rational. Data shows feasibility and proof of concept that supports the rationale for further development and testing of this approach. Subsequent .Phase II application will evaluate an assay developed in this Phase I project for application to screening of NSCLC. Thus, the primary goal of this application is to develop a novel blood test for NSCLC that can be rapidly translated into clinical practice. Success in this project will herald similar development in other malignant diseases. Relevance to Public Health. A blood test for lung cancer could improve the capability and cost-effectiveness of early detection as a viable strategy for reducing mortality from this disease. Relevance to Public Health. A blood test for lung cancer could improve the capability and cost-effectiveness of early detection as a viable strategy for reducing mortality from this disease. [unreadable] [unreadable] [unreadable]